I have bought a used HTC HD7 for about $330 in India. I love this phone, its so cool.

It shows O2 splash screen when it starts. I am using Vodafone Indian sim.

OS Ver: 7.0.7392.0
FW: 2250.09.16901.206

My questions:

1. How can I check if my phone was unlocked by Chevron or something else?
2. If I update my phone via Zune, will it re-lock again?
3. Any possibility to disable the 'Bing Search' button on the phone or reassign it with another app?